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John Mitchell - One of the best experts on this subject based on the ideXlab platform.

  • Tetanus Toxin-enhanced GABA Immunoreactivity in Living Neurons
    Journal of Histochemistry and Cytochemistry, 1998
    Co-Authors: John Mitchell
    Abstract:

    Analysis of the connectivity between different neuronal cell types is dependent on an appreciation of their dendritic and axonal arborizations. A detailed study of the dendrites and axons of GABAergic neurons has been thwarted by the lack of a suitable technique for enhancing GABA immunoreactivity. This article describes a procedure using Tetanus Toxin which, when applied to organotypic hippocampal cultures, considerably enhances the immunoreactivity in the dendrites and axons of the GABA- and somatostatin-containing neurons and clearly demonstrates the co-localization of GABA and somatostatin immunoreactivities in the same neuron. Tetanus Toxin was applied to the culture medium on Day 14 for a 24-hr period and the cultures were fixed at the end of Day 18. Tetanus Toxin-treated cultures (n = 30) or untreated cultures (n = 40) were incubated for either GABA or somatostatin immunoreactivity. Tetanus Toxin-treated cultures used for co-localization studies (n = 20) were incubated for both GABA and somatostati...

  • Tetanus Toxin-enhanced GABA immunoreactivity in living neurons
    Journal of Histochemistry and Cytochemistry, 1998
    Co-Authors: John Mitchell
    Abstract:

    Analysis of the connectivity between different neuronal cell types is dependent on an appreciation of their dendritic and axonal arborizations. A detailed study of the dendrites and axons of GABAergic neurons has been thwarted by the lack of a suitable technique for enhancing GABA immunoreactivity. This article describes a procedure using Tetanus Toxin which, when applied to organotypic hippocampal cultures, considerably enhances the immunoreactivity in the dendrites and axons of the GABA- and somatostatin-containing neurons and clearly demonstrates the co-localization of GABA and somatostatin immunoreactivities in the same neuron. Tetanus Toxin was applied to the culture medium on Day 14 for a 24-hr period and the cultures were fixed at the end of Day 18. Tetanus Toxin-treated cultures (n = 30) or untreated cultures (n = 40) were incubated for either GABA or somatostatin immunoreactivity. Tetanus Toxin-treated cultures used for co-localization studies (n = 20) were incubated for both GABA and somatostatin immunoreactivity.

Masakazu Nishimura - One of the best experts on this subject based on the ideXlab platform.

  • a mechanism of the thearubigin fraction of black tea camellia sinensis extract protecting against the effect of Tetanus Toxin
    Journal of Toxicological Sciences, 2002
    Co-Authors: Eiki Satoh, Sinichi Sawamura, Toshiaki Ishii, Yoshio Shimizu, Masakazu Nishimura
    Abstract:

    The aim of the present study was to elucidate the mechanism of the protective effect of black tea extract's thearubigin fraction against the action of Tetanus Toxin. The effects of thearubigin fraction extracted from a black tea infusion were examined for neuromuscular blocking action on Tetanus Toxin in mouse phrenic nerve-diaphragm preparations and on the binding of this Toxin to the synaptosomal membrane preparations of rat cerebral cortices. The interaction between Tetanus Toxin and thearubigin fraction was also investigated. Tetanus Toxin (4 μg/ml) abolished indirect twitches in mouse phrenic nerve-diaphragm preparations within 150 min. Thearubigin fraction mixed with Tetanus Toxin blocked the inhibitory effect of the Toxin. Mixing iodinated Toxin with thearubigin fraction inhibited the specific binding of [ 1 2 5 I]Tetanus Toxin to the synaptosomal membrane preparation. The effects of thearubigin fraction were dose-dependent. The elution profile of [ 1 2 5 ]Tetanus Toxin on Sephadex G-50 column chromatography was different from that of Toxin mixed with thearubigin fraction. These findings indicate that thearubigin fraction protects against the action of Tetanus Toxin by binding with the Toxin.

  • black tea extract thearubigin fraction counteracts the effect of Tetanus Toxin in mice
    Experimental Biology and Medicine, 2001
    Co-Authors: Eiki Satoh, Sinichi Sawamura, Toshiaki Ishii, Yoshio Shimizu, Masakazu Nishimura
    Abstract:

    The aim of this study was to find an inactivating substance for Tetanus Toxin in natural foodstuff. Tetanus Toxin (4 μg/ml) abolished indirect twitches in in vitro mouse phrenic nervediaphragm preparations within 2.5 hr. Hot water infusion of black tea mixed with Tetanus Toxin blocked the inhibitory effect of the Toxin. Mixing the Toxin with thearubigin fraction extracted from black tea infusion produced an identical result. Furthermore, thearubigin fraction mixed with the Toxin protected against the in vivo paralytic effect of the Toxin. Thearubigin fraction had no protective effect on other Toxins, such as tetrodoToxin and saxiToxin. The specific binding of [125I]Tetanus Toxin to rat cerebrocortical synaptosomes was inhibited by mixing iodinated Toxin with thearubigin fraction. These results imply that thearubigin fraction counteracts the effect of Tetanus Toxin by binding with Toxin, and also suggest that this fraction may be able to apply for prophylaxis of Tetanus.

Giampietro Schiavo - One of the best experts on this subject based on the ideXlab platform.

  • Tetanus Toxin fragment c binds to a protein present in neuronal cell lines and motoneurons
    Journal of Neurochemistry, 2008
    Co-Authors: Judit Herreros, Cesare Montecucco, Giovanna Lalli, Giampietro Schiavo
    Abstract:

    : Tetanus Toxin Fragment C Binds to a Protein Present in Neuronal Cell Lines and Motoneurons Tetanus neuroToxin is one of the most powerful protein Toxins known, acting in vivo at femtomolar doses. Two main factors determine its high potency: a protease activity restricted to a single intracellular substrate and its absolute neurospecificity. Whereas the enzymatic properties of Tetanus Toxin have been thoroughly defined, the nature of its neuronal receptor(s) and their involvement in the intracellular trafficking of Tetanus Toxin are poorly understood. Using binding and crosslinking experiments, we report here on the characterisation of an N-glycosylated 15-kDa interacting protein, which behaves as an integral membrane protein. This putative receptor specifically interacts with the binding domain (fragment C) of Tetanus Toxin and not with several related botulinum neuroToxins in spinal cord motoneurons and neuronal-like cell lines. Sialic acid-specific lectins antagonise the binding of Tetanus Toxin to the cell surface and to the 15-kDa protein, supporting the central role of sialic acid residues in the recognition process. Altogether, these results indicate the existence of a neuronal protein receptor for Tetanus Toxin whose identification is likely to constitute a key step in the analysis of the molecular machinery involved in the Toxin internalisation and retrograde transport.

  • Tetanus Toxin receptor. Specific cross-linking of Tetanus Toxin to a protein of NGF-differentiated PC 12 cells.
    FEBS Letters, 1991
    Co-Authors: Giampietro Schiavo, Giovanna Ferrari, Ornella Rossetto, Cesare Montecucco
    Abstract:

    A subclone of rat pheochromocytoma cells expresses high affinity receptors for Tetanus Toxin on differentiation with NGF [Walton, K.M., Sandberg, K., Rogers, T.B. and Schnaar, R.L. (1988) J. Biol. Chem. 263, 2055–2063]. In the presence of protein cross-linking agents, [125I]Tetanus Toxin, bound to these cells at 0°C, forms a cross-linked product with apparent molecular weight of 120 kDa. The formation of [125I]Tetanus Toxin conjugate involves the heavy chain of the Toxin, is prevented by cold Toxin and it is largely reduced by pretreating cells with proteases, The cross-linked product is formed only upon incubation of the Toxin with NGF-differentiated cells. These results suggest that a protein with apparent molecular weight of 20 kDa is involved in the neurospecific binding of Tetanus Toxin.

  • On the role of polysialoglycosphingolipids as Tetanus Toxin receptors. A study with lipid monolayers.
    FEBS Journal, 1991
    Co-Authors: Giampietro Schiavo, Rudy A. Demel, Cesare Montecucco
    Abstract:

    Lipid monolayers of different compositions were used to study the interaction of Tetanus Toxin with membrane lipids and to evaluate the role of polysialoglycosphingolipids as membrane receptors. At neutral pH, the Toxin binds to dioleoylglycerophosphocholine monolayers and inserts into the phospholipid layer. This effect is potentiated by acidic phospholipids without an apparent preference for a single class of phospholipids. Polysialoglycosphingolipids further increase the fixation and penetration of Tetanus Toxin in lipid monolayers, but no specific requirement for a particular ganglioside was identified. The ganglioside effect is abolished in the presence of other nervous tissue lipids: cerebrosides and glycosphingolipid sulfates are partially responsible for this effect. The penetration of Tetanus Toxin in the lipid monolayer is pH dependent. It increases with lowering pH, it is facilitated by acidic phospholipids and by glycosphingolipid sulfates and it is mediated both by hydrophobic and electrostatic interactions as deduced from an analysis of the effect of ionic strength. Fragment B of Tetanus Toxin (light chain plus the 50-kDa N-terminal part of the heavy chain) is involved in the low-pH-driven lipid interaction of the Toxin. On the basis of the present findings, the possible role of polysialoglycosphingolipids in the neurospecific binding of Tetanus Toxin is discussed.

  • An intact interchain disulfide bond is required for the neurotoxicity of Tetanus Toxin.
    Infection and Immunity, 1990
    Co-Authors: Giampietro Schiavo, Emanuele Papini, G Genna, Cesare Montecucco
    Abstract:

    Tetanus Toxin is composed of a heavy chain (100 kDa) and a light chain (50 kDa) held together by a single interchain disulfide bridge. An additional intrachain disulfide is present in the carboxy-terminal part of the heavy chain. Reduction of the two disulfide bonds in Tetanus Toxin with both chemical and proteinaceous reducing agents was studied. Dithiothreitol and 2-mercaptoethanol cleaved both the inter- and intrachain disulfide bridges of the Toxin, while glutathione and cysteine were ineffective. Specific reduction of the single interchain disulfide link was achieved with the thioredoxin-thioredoxin reductase system, thus indicating that this bond is exposed at the protein surface. Also, dead or permeabilized cells were able to reduce the Toxin. Such reduced Toxin bound to neuronal membranes as well as the native Toxin but was not neurotoxic. These findings open the possibility that reduction by cytoplasmic agents released by dead cells contributes to detoxification of Tetanus Toxin. Moreover, together with the notion that the light chain is the active form of the Toxin in the cytoplasm, these results suggest that the interchain disulfide bond of Tetanus Toxin plays a role in nerve cell penetration.

Victoria Heimermcginn - One of the best experts on this subject based on the ideXlab platform.

  • decreased dendritic spine density as a consequence of Tetanus Toxin light chain expression in single neurons in vivo
    Neuroscience Letters, 2013
    Co-Authors: Victoria Heimermcginn, Anita C H Murphy, Susan M Dymecki, Paul Young
    Abstract:

    Abstract Tetanus Toxin light chain has been used for some time as a genetically-encoded tool to inhibit neurotransmission and thereby dissect mechanisms underlying neural circuit formation and function. In addition to cleaving v-SNARE proteins involved in axonal neurotransmitter release, Tetanus Toxin light chain can also block activity-dependent dendritic exocytosis. The application of Tetanus Toxin light chain as a research tool in mammalian models, however, has been limited to a small number of cell types. Here we have induced expression of Tetanus Toxin light chain in a very small number of fluorescently labeled neurons in many regions of the adult mouse brain. This was achieved by crossing SLICK (single-neuron labeling with inducible cre-mediated knockout) transgenic lines with RC::Ptox mice that have Cre recombinase-controlled expression of the Tetanus Toxin light chain. Using this system we have examined the cell-autonomous effects of Tetanus Toxin light chain expression on dendritic spines in vivo . We find that dendritic spine density is reduced by 15% in Tetanus Toxin expressing hippocampal CA1 pyramidal cells, while spine morphology is unaltered. This effect is likely to be a consequence of inhibition of activity-dependent dendritic exocytosis and suggests that on-going plasticity-associated exocytosis is required for long-term dendritic spine maintenance in vivo .

Eiki Satoh - One of the best experts on this subject based on the ideXlab platform.

  • a mechanism of the thearubigin fraction of black tea camellia sinensis extract protecting against the effect of Tetanus Toxin
    Journal of Toxicological Sciences, 2002
    Co-Authors: Eiki Satoh, Sinichi Sawamura, Toshiaki Ishii, Yoshio Shimizu, Masakazu Nishimura
    Abstract:

    The aim of the present study was to elucidate the mechanism of the protective effect of black tea extract's thearubigin fraction against the action of Tetanus Toxin. The effects of thearubigin fraction extracted from a black tea infusion were examined for neuromuscular blocking action on Tetanus Toxin in mouse phrenic nerve-diaphragm preparations and on the binding of this Toxin to the synaptosomal membrane preparations of rat cerebral cortices. The interaction between Tetanus Toxin and thearubigin fraction was also investigated. Tetanus Toxin (4 μg/ml) abolished indirect twitches in mouse phrenic nerve-diaphragm preparations within 150 min. Thearubigin fraction mixed with Tetanus Toxin blocked the inhibitory effect of the Toxin. Mixing iodinated Toxin with thearubigin fraction inhibited the specific binding of [ 1 2 5 I]Tetanus Toxin to the synaptosomal membrane preparation. The effects of thearubigin fraction were dose-dependent. The elution profile of [ 1 2 5 ]Tetanus Toxin on Sephadex G-50 column chromatography was different from that of Toxin mixed with thearubigin fraction. These findings indicate that thearubigin fraction protects against the action of Tetanus Toxin by binding with the Toxin.

  • black tea extract thearubigin fraction counteracts the effect of Tetanus Toxin in mice
    Experimental Biology and Medicine, 2001
    Co-Authors: Eiki Satoh, Sinichi Sawamura, Toshiaki Ishii, Yoshio Shimizu, Masakazu Nishimura
    Abstract:

    The aim of this study was to find an inactivating substance for Tetanus Toxin in natural foodstuff. Tetanus Toxin (4 μg/ml) abolished indirect twitches in in vitro mouse phrenic nervediaphragm preparations within 2.5 hr. Hot water infusion of black tea mixed with Tetanus Toxin blocked the inhibitory effect of the Toxin. Mixing the Toxin with thearubigin fraction extracted from black tea infusion produced an identical result. Furthermore, thearubigin fraction mixed with the Toxin protected against the in vivo paralytic effect of the Toxin. Thearubigin fraction had no protective effect on other Toxins, such as tetrodoToxin and saxiToxin. The specific binding of [125I]Tetanus Toxin to rat cerebrocortical synaptosomes was inhibited by mixing iodinated Toxin with thearubigin fraction. These results imply that thearubigin fraction counteracts the effect of Tetanus Toxin by binding with Toxin, and also suggest that this fraction may be able to apply for prophylaxis of Tetanus.